Abstract: A computer-implemented method, a computer program product, and a computer system for optimizing timing for migrating data. The computer system sets a migration required flag for each of first tapes, in response to determining an estimated time period required for data migration from the first tapes to second tapes being smaller than an expiration time period of the first tapes. The computer system sets the migration required flag for a respective one of the first tapes, in response to determining the estimated time period being not smaller than the expiration time period and a predetermined time period has passed for the respective one of the first tapes. Data on tapes that migration required flags are set is to be migrated to the second tapes.

Abstract: A computer-implemented method for writing data to a tape medium, includes: writing a file of a first content to the tape medium; writing at least a part of the file of a second content to the tape medium, the second content being obtained by updating the first content; and writing an index including first metadata and second metadata to the tape medium, the first metadata being metadata of the file of the first content, the second metadata being metadata of the file of the second content.

Abstract: A computer-implemented method for faster unmount of tape drives includes generating a batch file to be migrated from a primary storage to a tape media acting as a secondary storage. The size of the batch file is determined based on an amount of available storage space on the tape media between a position in a longitudinal direction of storage (LPOS) and longitudinal position three (LP3) on the tape media. The computer-implemented method further includes migrating the batch file from the primary storage to the tape media mounted on a tape drive. Upon completion of migrating the batch file, the LPOS is within a predetermined threshold distance of LP3 on the tape media.

Abstract: Communicating data with a medium is provided. A cache is provided for storing target data of a file identified by an access request from an application of a host. The cache is divided into a read cache, a write cache, and an index cache. Responsive to receiving the access request: the medium is loaded onto a drive using a file system; target data is stored to the write cache and to the read cache; and the index file stored in the index cache is updated to reflect position metadata about the target data stored in the write cache. Responsive to initiating unloading of the medium from the drive: the updated index file stored in the index cache is written to the index partition of the medium; and the target data stored in the write cache is written onto a data partition of the medium without using the file system.

Abstract: Aspects of the present disclosure relate to managing index writes within a tape. A determination can be made that a change was made to at least one file stored within a tape medium while the tape medium was mounted within a tape drive. In response to the determination, an index can be written to a data partition of the tape medium. A determination can be made whether the change included any changes to a file at least equal to a threshold hierarchy level. In response to determining that the change did not include any changes to a file at least equal to the threshold hierarchy level, a first instruction can be issued to the tape drive to reposition the tape medium to the end of the tape. A second instruction can be issued to the tape drive to perform an unthread operation at low tension to rewind the tape medium.

Abstract: Method, computer program product, and system embodiments of the present disclosure may include a computing device which may set a predetermined flag on data to be copied from a primary storage tier and a secondary storage tier. The computing device may identify a first portion of the flagged data as being in a pre-migrated state stored on the primary storage tier and migrate the flagged pre-migrated data from the primary storage tier to a target medium. The computing device may identify a second portion of the flagged data as being in a migrated state stored on the secondary storage tier. The computing device may recall the flagged migrated data from the secondary storage tier to the primary storage tier and migrate the recalled migrated data from the primary storage tier to the target medium.

Abstract: An embodiment of the invention may include a method, computer program product and system for saving data received from a host computing device to a storage system. The storage system includes at least one processor and at least one storage. An embodiment may include storing the received data to the storage on a record basis. A record includes a record header including information indicative of an implemented compression method of the record. An embodiment may include monitoring a processing load of the at least one processor. In response to the processing load being less than a predetermined level, an embodiment may include further compressing the record utilizing a high-ratio compression method based on the record requiring further compression. An embodiment may include updating the record header information to reflect details of the utilized a high-ratio compression method. An embodiment may include storing the further compressed record to the storage.

Abstract: A computer-implemented method, a computer program product, and a computer system for reordering a sequence of files based on compression rates in data transfer. A host determines predicted compression rates of first files that are to be saved onto a first tape, based on a relationship between compression rates and file attributes of second files that have been saved on a second tape. The host reorders a sequence of the first files stored in host cache storage and generates a new sequence of transferring the first files from the host cache storage to the tape drive hosting the first tape, based on the predicted compression rates of the first files. The host transfers the first files to the tape drive hosting the first tape and writes the first files to the first tape, according to the new sequence.

Abstract: Aspects of the present disclosure relate to synchronizing data writes. An update to a file stored on a virtual tape image is received. A position and length of the file is recorded as an invalid data area. The virtual tape image is then synchronized with a tape. The invalid data area is then released from the virtual tape image.

Abstract: Provided is a method, computer program product, and system for enumerating files on a tape medium and a cache storage device. The method includes receiving a command to enumerate a directory stored on a tape medium. The directory includes a plurality of files. The method further includes determining that the directory has been at least partially cached to a cache storage device. The method further includes determining, for each file of the directory that is stored in the cache storage device, whether the file has been enumerated. In response to determining that the file has not been enumerated, the method includes returning information of the file as a response to the command. The method further includes mounting the tape medium in parallel to retrieving data from the cache storage device.

Abstract: Provided is a method for writing and deleting files on a tape medium and a cache storage device. The method includes receiving a command to write one or more files of a directory to a tape medium. The method further includes identifying a cache limit associated with the tape medium. The method further comprises determining whether the amount of data of the directory that is already on the cache storage device exceeds the cache limit. In response to the amount of data not exceeding the cache limit, the method includes writing data of the one or more files to the cache storage device and the tape medium in parallel.

Abstract: A method, computer system, and a computer program product for objective-based compression level change is provided. The present invention may include storing a volume in a storage device, wherein the stored volume is compressed using an initial compression level. The present invention may also include checking a last access time of the stored volume in the storage device at a regular interval. The present invention may further include, in response to determining, based on the checked last access time, that the stored volume is not accessed at the regular interval, recompressing the stored volume in the storage device using a higher compression level, wherein the higher compression level includes a higher compression ratio than a compression ratio associated with the initial compression level.

Abstract: A computer-implemented method for managing a first storage library and a second storage library, according to one embodiment, includes associating a first physical tape and a second physical tape with a logical tape. The associating includes writing a first identifier to an index of the logical tape. The first identifier represents the first physical tape and the first storage library. The associating further includes writing a second identifier to the index of the logical tape. The second identifier represents the second physical tape and the second storage library. The computer-implemented method further includes storing the index of the logical tape in memory, and displaying the logical tape by reading the index from memory as a file system.

Abstract: Aspects of the present disclosure relate to synchronizing data writes. An update to a file stored on a virtual tape image is received. A position and length of the file is recorded as an invalid data area. The virtual tape image is then synchronized with a tape. The invalid data area is then released from the virtual tape image.

Abstract: A computer-implemented method, according to one approach, includes: receiving a request to read a plurality of files from a magnetic tape, and obtaining a tape directory which identifies regions on the magnetic tape in which the files are stored. The tape directory is used to map each of the files to one of the regions on the magnetic tape in which the respective file is stored. A first subset of the files stored in a same first region on the magnetic tape is also sorted into a first order. The computer-implemented method further includes simultaneously: sorting a second subset of the files stored in a same second region on the magnetic tape into a second order, and instructing a tape drive to read each of the files in the first subset according to the first order.

Abstract: The method, computer program product, and computer system may include a computing device which may generate a list of data to be copied from a plurality of source media to a target medium. The computing device may identify a first type of data in the generated list of data with the first type of data being pre-migrated data. The computing device may reclaim the first type of data from a primary storage tier to the target medium with the target medium being associated with the first drive. The computing device may identify a second type of data in the generated list of data, the second type of data being migrated data, and reclaim the second type of data from at least one secondary source medium to the target medium using the first drive and a second drive. The secondary source medium may be associated with the second drive.

Abstract: Aspects of the present disclosure relate to a method for timing index write to a tape medium of a tape system. Index write timing data that specifies index write timing based on file metadata attributes is stored. Metadata attributes of a first file are analyzed to determine whether a first index should be written at a first time based on the index write timing data. In response to determining that an index should be written, the first index is written to the tape medium at the first time.

Abstract: Embodiments provide a method, a system, and a computer program product for performing copy operations of one or more data units in a hierarchical storage management (HSM) system. The HSM system includes an upper layer and a lower layer. The upper layer includes multiple storage nodes having a grid configuration. The method comprises scheduling a copy operations of multiple data units each of which is stored in at least one of the multiple storage nodes such that loads on the copy operations are distributed among the multiple storage nodes in which the multiple data units are stored and copying the multiple data units to the lower layer in accordance with the scheduling.

Abstract: A computer-implemented method, according to one embodiment, includes: sending one or more instructions to calculate a combined size of fragments included in the fragmented files, sending one or more instructions to designate a portion of cache which corresponds to at least the combined size of the fragments, sending one or more instructions to send a copy of each non-fragmented file from a first drive directly to a second drive in which the second sequential storage medium is loaded, sending one or more instructions to use the designated portion of the cache to accumulate the fragments included in the fragmented files, and sending one or more instructions to send a copy of each of the fragments corresponding to a given fragmented file from the cache to the second drive in response to determining that all of the fragments corresponding to the given fragmented file have been accumulated in the cache.

Abstract: The time required for recalling the file is reduced when the file is written in a mounted plurality of tapes in comparison to recalling the file when written in a non-mounted plurality of tapes. In the non-mounted state, criteria does not typically exist in order to recall the written file within the plurality of tapes. Embodiments of the present invention provide systems and methods for recalling files based on criteria which considers: the mounted state of a tape; the type of tape; the type of available tape drive; the number of files included in a tape; and the location of the written file in a tape.